Laser-Aided Manufacturing: Atom to Application
257
Fig. 3 Basic laser mechanism [1]
GM for laser heat treatment of steering columns. During the past decade, German auto
manufacturers have installed hundreds of lasers for body-in-white welding purposes.
2 Why Lasers Are Attractive for Manufacturing?
The basic mechanism of a laser is shown in Fig. 3. Laser light is a stream of photons
that interact with surface electrons of the materials it is processing. This mechanism
is known as “inverse bremsstrahlung.” Laser light, unlike conventional machine
tools, does not have any mass or inertia. The beam can be focused to a very small
spot concentrating the energy exceeding 10
5 W/cm
2 . It is probably one of the few
sources of energy with such concentrated energy capable of melting and ablating
many of the engineering materials. Energy can be delivered through vacuum, air, or
fiber. The beam can be shaped to conform to a particular surface. Shaping can be
done both temporally and spatially. This characteristic provides enormous flexibility
for manufacturing applications. Energy density can be varied with optics based on
the power density needed for the specific manufacturing process. For example, heat
treatment requires 10
3 W/cm
2 whereas welding requires 10
6 W/cm
2 . Same laser can
provide both intensity levels with simple optics. The optical beam can also provide
photolytic processes breaking molecules by matching the wavelength of vibration of
the molecular bonds. Coherence and spectral purity allow strange non-linear optical
effects. Polarization, frequency doubling, diffraction, and multi-photon phenomena
all found their way into the manufacturing floor. Moreover, optical energy source is
highly amenable to automation.
3 Laser-Aided Manufacturing
Initially, lasers were dubbed as “Solution looking for Problem” but since 1070s, it
has been used extensively for various applications from [A to Z] atom splitting to
zapping of eyes. However, as shown in Fig. 2, material processing and manufacturing
257
Fig. 3 Basic laser mechanism [1]
GM for laser heat treatment of steering columns. During the past decade, German auto
manufacturers have installed hundreds of lasers for body-in-white welding purposes.
2 Why Lasers Are Attractive for Manufacturing?
The basic mechanism of a laser is shown in Fig. 3. Laser light is a stream of photons
that interact with surface electrons of the materials it is processing. This mechanism
is known as “inverse bremsstrahlung.” Laser light, unlike conventional machine
tools, does not have any mass or inertia. The beam can be focused to a very small
spot concentrating the energy exceeding 10
5 W/cm
2 . It is probably one of the few
sources of energy with such concentrated energy capable of melting and ablating
many of the engineering materials. Energy can be delivered through vacuum, air, or
fiber. The beam can be shaped to conform to a particular surface. Shaping can be
done both temporally and spatially. This characteristic provides enormous flexibility
for manufacturing applications. Energy density can be varied with optics based on
the power density needed for the specific manufacturing process. For example, heat
treatment requires 10
3 W/cm
2 whereas welding requires 10
6 W/cm
2 . Same laser can
provide both intensity levels with simple optics. The optical beam can also provide
photolytic processes breaking molecules by matching the wavelength of vibration of
the molecular bonds. Coherence and spectral purity allow strange non-linear optical
effects. Polarization, frequency doubling, diffraction, and multi-photon phenomena
all found their way into the manufacturing floor. Moreover, optical energy source is
highly amenable to automation.
3 Laser-Aided Manufacturing
Initially, lasers were dubbed as “Solution looking for Problem” but since 1070s, it
has been used extensively for various applications from [A to Z] atom splitting to
zapping of eyes. However, as shown in Fig. 2, material processing and manufacturing